A21 Two galaxies form a double system in the slit, separated in A21 projection by 6.8 arcsec (16kpc). Galaxy a (to the SE) is the A21 brighter, but galaxy b has an asymmetric diffuse envelope (see A21 Porter, Schneider & Hoessel, 1991, Cat. ). A115 The central cluster galaxy contains the radio source 3C 28. The A115 ROSAT HRI image of this cluster shows two components to the A115 X-ray morphology, suggesting it to be a double cluster. The A115 smaller component to the south is centred on a galaxy at A115 RA 00h56m00s, Dec. 26{deg}20'37"(J2000), but we have taken a A115 spectrum for 3C 28 at the centre of the main X-ray component. RXJ0107.4+3227 This cluster is also known as the group IV Zw 038 and the galaxy RXJ0107.4+3227 observed (NGC 383) is associated with the radio source 3C31. RXJ0107.4+3227 Colina & Perez-Fournon (1990ApJS...72...41C) note a central dust RXJ0107.4+3227 lane in this galaxy. A168 The observed galaxy is offset by 3-4 arcmin from the X-ray A168 centroid, but the X-ray image of the cluster is broad with no A168 tight core, and the galaxy observed is clearly the brightest A168 cluster galaxy. RXJ0123.2+3327 (NGC 499) and RXJ0123.6+3315 (NGC 507) form a double system. RXJ0123.6+3315 See RXJ0123.2+3327 A262 The central cluster galaxy is known from ground-based images to A262 be bifurcated by a central dust lane (Colina & Perez-Fournon A262 1990ApJS...72...41C), which splits the galaxy continuum light in A262 our slit into two components separated in projection by 1.6arcsec A262 (0.8 kpc). The line emission is spatially centred exactly on the A262 dust lane separating these two components. A272 We have taken a spectrum of the brightest dominant galaxy, A272 although a second candidate dominant galaxy lies 2.4 arcmin to A272 the N. A400 The dominant galaxies are a dumbbell system separated by A400 16.2 arcsec (~11 kpc) in projection, and are associated with the A400 twin radio source 3C75 Z808 The observed galaxy is associated with the radio source 4C+01.06. A407 Several bright galaxies appear to be embedded in a diffuse A407 optical halo within a region of diameter ~60 kpc. We present the A407 spectrum only of the brightest galaxy. RXJ0338.7+0958 is the cluster 2A 0335+096. RXJ0341.3+1524 The observed galaxy is catalogued as 111 Zw 054. A520 This is a bimodal cluster, and we have observed the brightest A520 (to the SW of the cluster) of three dominant galaxies. This A520 cluster was detected in the Einstein Medium Sensitivity Survey A520 (EMSS) (Stocke et al., 1991, Cat. ). A566 is associated with the radio source 4C+63.10. A576 Galaxy b, the more southerly of the two dominant galaxies A576 observed, is the more probable central cluster galaxy. A586 Two galaxies lie on our slit, separated by only 5.1 arcsec A586 (20 kpc) in projection. We present only the spectrum of the main A586 galaxy to the NW of the two. RXJ0751.3+5012 This cluster has a disturbed X-ray morphology. The three galaxies RXJ0751.3+5012 for which we have spectra are the bright more southerly galaxy RXJ0751.3+5012 (a) and both components of a dumbbell system to the north [galaxy RXJ0751.3+5012 b to the E and c to the W of the pair, separated in projection by RXJ0751.3+5012 22.1 arcsec (15 kpc)]. A602 We have taken the spectrum of each of the two equally bright A602 dominant galaxies in this double cluster. A671 We have taken the spectrum only of the larger, brighter galaxy A671 surrounded by diffuse optical emission, which we assume is the A671 BCG. A second very bright dominant galaxy lies 3.1 arcmin to the A671 SE. A665 There is a second, less bright galaxy also within the slit, A665 10.6 arcsec (42 kpc) to the SE of the dominant galaxy. We present A665 only the spectrum of the dominant galaxy. A689 This galaxy was observed in C95, but the redshift given in that A689 paper is wrong. The spectrum is very noisy, and shows a very blue A689 galaxy with uncertain stellar absorption features. The new A689 redshift has been determined by Ebeling, Henry & Mullis A689 (1999, in prep.), and is confirmed as the redshift of the cluster A689 from spectra of two other galaxies. The X-ray source is A689 coincident with a moderately bright radio source, which could A689 contribute significantly to the X-ray flux of the total cluster A689 emission. A750 The cluster contains an AGN at the same redshift. There are two A750 equally bright dominant galaxies, separated by 94 arcsec, but we A750 only present a spectrum of the galaxy to the SE; the other lies A750 at RA 09h 09m 07s, Dec 10{deg} 67' 51" (J2000). This cluster and A750 the AGN were detected in the EMSS (Stocke et al., 1991, A750 Cat. ). A763 The identification of this source is confused. Our optical A763 identification of the point-like object at the X-ray centroid A763 (RA 09h 12m 31.0s, Dec. 15{deg} 55' 25"; J2000) is of a star, A763 despite it being associated with a moderate, spatially extended A763 radio source. The spectrum presented in this paper is of the A763 dominant galaxy 4.7 arcmin to the N of this star which, despite A763 being the nearest obvious BCG, is probably too far to be A763 associated with the X-ray source. A773 The two galaxies appear to be equally dominant. RXJ1000.5+4409 Galaxy a is the more likely central dominant galaxy. Z3179 There is an IRAS-detected, foreground (z=0.032) spiral Z3179 galaxy 110 arcsec to the NW of the observed galaxy. A1023 Position of observed galaxy revised from A92. A1035 The cluster is contaminated by a foreground group at z=0.067 A1035 (Maurogordato et al., 1997A&AS..123..411M). A1185 This X-ray source is very extended. Galaxy a is the brightest of A1185 the three observed, and agrees with the X-ray centroid. A1190 We have taken a spectrum only of the brighter of two nearby A1190 dominant galaxies, that to the SE of the pair; the radio source A1190 4C+41.23 is associated with the other galaxy. A1201 We have taken a spectrum of the galaxy closest to the X-ray A1201 centroid. A brighter galaxy to the SE probably belongs to a A1201 foreground cluster. A1204 Note that the declination is incorrectly given in A92 as +11{deg} A1361 The observed galaxy is associated with the radio source 4C+46.23. A1413 A second, smaller galaxy also lies on the slit, at a separation A1413 of only 9.5 arcsec (31 kpc) to the N. We present the spectrum A1413 only of the main galaxy. Maurogordato et al. A1413 (1997A&AS..123..411M) note the presence of a small foreground A1413 group of galaxies at z=0.1. A1437 The main galaxy is close dumbbell, of separation 3.2" (10kpc) Z4803 This source is also catalogued as the poor group MKW4. RXJ1206.5+2810 The observed galaxy (NGC 4104) is a double galaxy in the group RXJ1206.5+2810 MKW4s, the two components being separated by 2.8 arcsec (2.2kpc). RXJ1206.5+2810 The emission-line system spans the two systems. The cluster is an RXJ1206.5+2810 EMSS source (Stocke et al., 1991, Cat. ). Z4905 The observed galaxy has a very large and asymmetric halo on the Z4905 POSS. Z5029 The observed galaxy is not associated with the radio source Z5029 4C+04.41 which lies in this cluster RXJ1223.0+1037 The observed galaxy (NGC 4325) may have nuclear activity, as the RXJ1223.0+1037 X-ray source is barely extended in archival PSPC data, although RXJ1223.0+1037 the line emission is quite muted. Alternatively, it could be an RXJ1223.0+1037 example of a highly focused cooling flow in a low-luminosity RXJ1223.0+1037 group. A1553 We have taken the spectrum of each of the two equally dominant A1553 bright galaxies in this double cluster. RXJ1230.7+1220 is M87 in the Virgo cluster, and associated with the radio source RXJ1230.7+1220 3C274. A1656 This is the Coma cluster, and we have taken the spectrum only of A1656 the more western of the two dominant galaxies, NGC 4874 . A1668 The measured redshift is significantly different from that in A1668 Rhee & Katgert (1988A&AS...72..243R). A1672 Position of observed galaxy revised from A92. A1677 Previously noted in A92 as Z5694. Position revised from original. A1682 The two galaxies are equally dominant. A1703 Galaxy a is the more likely central dominant galaxy. RXJ1320.1+3308 Two equally bright galaxies lie along our slit position, with a RXJ1320.1+3308 projected separation of 38.1 arcsec (38 kpc). A1758 This double cluster has its two components listed separately in A1758 Paper 1. We list here the dominant galaxy associated only with A1758 A 1758a, which produces approximately 40 per cent of the combined A1758 luminosity; there is a bright less dominant galaxy also at A1758 RA 13h 32m 51.9s, Dec. 50{deg} 31' 36" (J2000). A1763 The observed galaxy is associated with the radio source 4C+41.26. A1775 The two dominant galaxies form a double system, separated in A1775 projection by 21.1 arcsec (~40 kpc); they are associated with the A1775 radio source 4C+26.41 A1795 The observed galaxy is associated with the radio source 4C+26.42. A1831 The cluster shows a foreground cluster at z=0.062 A1831 (Maurogordato et al. 1997A&AS..123..411M). A1835 We present three different observations of the same central A1835 cluster galaxy, one from A92, and two from our May observing run A1835 at slightly different position angles. A1914 This is a complex binary cluster, and we have only taken a A1914 spectrum of the brighter (to the SW) of the two dominant A1914 galaxies. The radio source 4C+38.39 is probably a radio halo and A1914 hence not associated with the observed galaxy. RXJ1440.6+0327 The source is also catalogued as the poor group MKW8, and the two RXJ1440.6+0327 galaxies observed are also catalogued as Arp 171. The galaxy (a) RXJ1440.6+0327 to the SE is probably the dominant galaxy; the two galaxies on RXJ1440.6+0327 the slit are separated in projection by 59.2 arcsec (44 kpc). RXJ1449.5+2746 The observed galaxy is offset from the centroid of this RXJ1449.5+2746 relatively compact X-ray source, indicating that it may well be RXJ1449.5+2746 unrelated to the X-ray emission. A1983 Two equally bright dominant galaxies lie along the slit position, A1983 separated by 92.6 arcsec (112 kpc). Z7160 This cluster is the EMSS cluster MS1455+223 (Stocke et al., 1991, Z7160 Cat. ). A2009 The cluster contains the radio source 4C+21.44, which is, A2009 however, unlikely to be associated with the observed galaxy. A2034 Galaxy b is the more likely central dominant galaxy. A2029 The observed galaxy is associated with the radio source 4C+06.53. A2033 There are two galaxies along the slit; we take the spectrum of A2033 the main galaxy to the NE as the central dominant galaxy. The A2033 galaxy 38 arcsec to the SW is a foreground AGN at a redshift A2033 of 0.038. A2052 The observed galaxy is associated with 3C317. A2055 There are three equally bright dominant galaxies; a and b lie A2055 along the same slit position, separated in projection by 80arcsec A2055 (200 kpc). None of these redshifts agrees with the previously A2055 published redshift of 0.053 in Struble & Rood (1991, A2055 Cat. ). A2064 The redshift of the observed galaxy is inconsistent with the A2064 previously published redshift of 0.1074 from Owen, White & A2064 Thronson (1988AJ.....95....1O), from which the cluster redshift A2064 has been derived. We find no evidence to support the previous A2064 redshift in our spectrum. A2061 This bimodal cluster is highly extended. We have observed the two A2061 equally bright dominant galaxies either side of the X-ray A2061 centroid. RXJ1522.0+0741 The source is also catalogued as the poor group MKW3s. The RXJ1522.0+0741 central galaxy (NGC 5920) is associated with the radio source RXJ1522.0+0741 3C318.1. A2065 There are three galaxies along our chosen slit position; galaxy a A2065 is 52 arcsec to the NW, and galaxy c lies 21 arcsec to the SE of A2065 the much less bright galaxy b. Galaxies a and c are both dominant A2065 galaxies. A2069 This cluster is particularly extended, and the X-ray centroid A2069 lies between two bright galaxies; one the central dominant galaxy A2069 in A2069 (galaxy a). Our spectrum of the second bright galaxy at A2069 RA 15h 24m 22.7s and Dec 29{deg} 57' 25" (J2000) shows it to be a A2069 foreground active galaxy at a redshift of 0.076. This galaxy may A2069 be a weak contributor to the total X-ray emission from the A2069 cluster, and we note that its redshift suggests that it may be a A2069 outlying member of the nearby cluster A2061. Also, along our A2069 slit position for galaxy a are two other cluster galaxies (b and A2069 c) 26 arcsec to the NW of galaxy a, and separated from each other A2069 by only 4.1 arcsec (11 kpc). This cluster is an EMSS cluster A2072 The X-ray centroid is offset by 2.5' from the observed galaxy, A2072 which is the nearest obvious BCG. A2111 This cluster has two equally dominant central galaxies, separated A2111 by 47 arcsec (220 kpc) in projection. The X-rays from this A2111 cluster are elongated (Wang, Ulmer & Lavery 19977MNRAS.288..702W) A2142 We have taken the spectrum of each of the two equally bright A2142 dominant galaxies in this binary cluster. They lie along the same A2142 slit position, separated by 104 arcsec (238 kpc). A2146 The emission-line ratios of the observed galaxy and a pointed A2146 X-ray observation of the cluster show that this galaxy contains A2146 an AGN (Allen 1995MNRAS.276..947A), but the deep ROSAT HRI image A2146 shows that the majority of the flux is from extended cluster gas. A2151 This cluster is resolved into two components by the RASS because A2151 of its low redshift. We list here the dominant galaxy in A2151 a, A2151 which produces 93 per cent of the combined luminosity of the A2151 system. RXJ1604.9+2356 The source is also catalogued as the poor group AWM4. The RXJ1604.9+2356 observed galaxy is associated with the radio source 4C+24.36. A2199 The observed galaxy (NGC 6166) is associated with 3C338. A2204 Two galaxies lie along our slit position, separated by 4 arcsec A2204 (14 kpc). The galaxy to the SE has the strong extended line A2204 emission associated with it, and we present the spectrum of only A2204 this galaxy. A2219 Galaxy b is the most likely central dominant galaxy. A2228 The X-ray flux and centroid of the cluster source is likely to be A2228 significantly affected by the presence of an AGN within, but not A2228 at the centre of the cluster (see A92). RXJ1657.8+2751 This source is also catalogued as the poor group AWM5. A2256 This cluster is a well-known binary system. Galaxies a and b A2256 form a common system, separated by 6.6 arcsec (~10kpc), and A2256 galaxy c is 19 arcsec further to the NW along this slit. Galaxy A2256 d is a bright dominant galaxy to the E of galaxies a, b and c, A2256 and the best candidate for a single central cluster galaxy. A2249 This cluster is a binary system and relatively extended in the A2249 X-ray. We have only taken a spectrum of one of the two dominant A2249 giant elliptical galaxies (the more eastern), as it is in better A2249 agreement with the X-ray centroid. The cluster is associated with A2249 the radio source 4C+34.45. A2255 This cluster has two dominant galaxies separated by 53.7 arcsec A2255 (109kpc); each of these galaxies appears to be a very close A2255 dumbbell in its own right. RXJ1733.0+4345 The observed galaxy (IC 1262) is associated with 4C+43.46. RXJ1740.5+3539 Two dominant galaxies lie along this slit position, separated by RXJ1740.5+3539 38.9 arcsec (~45 kpc); galaxy b looks from the POSS to be the RXJ1740.5+3539 more likely candidate for the central cluster galaxy. Z8276 is an uncatalogued radio-loud galaxy. Z8338 This cluster has two close central galaxies; we observed the Z8338 brighter to the east of the pair. A2318 The X-ray centroid is offset from the galaxy observed, but note A2318 that the galaxy position given in A92 is in error. There is a A2318 Seyfert 1 galaxy coincident with the X-ray centroid at the A2318 redshift of the cluster, z=0.14 (Edge, private communication), A2318 so this source is significantly contaminated. RXJ2114.1+0234 The observed galaxy (IC 1365) has an asymmetric optical halo on RXJ2114.1+0234 the POSS image, and is contained in the poor group 11 Zw 108. A2443 The cluster contains two dominant galaxies. We have only taken a A2443 spectrum of the brighter galaxy, which is a better candidate for A2443 the BCG: the other lies 2 arcmin to the NW. This fainter galaxy A2443 is associated with 4C+17.89. Z8852 This highly extended X-ray source is the Pegasus Group. The Z8852 centre is occupied by two equally dominant galaxies: we have Z8852 observed NGC 7499, and the other central galaxy NGC 7503 (which Z8852 we did not observe) is associated with the radio source 4C+07.61. Z8852 NGC 7499 is closer to the X-ray emission centroid. A2572a This source is also catalogued as the compact group Hickson 94. A2572a There are two galaxies along our slit, separated in projection by A2572a 33.7 arcsec (37 kpc). Galaxy a is the brighter, but galaxy b is A2572a embedded in an asymmetric optical halo on the POSS. A2572b There is a second, higher redshift cluster in the background of A2572b A2572b that may contribute to the total X-ray flux measured from A2572b this cluster (Ebeling, Mendes de Oliveira & White A2572b 1995MNRAS.277.1006E). A2626 This cluster has two close galaxies separated by 3.4 arcsec A2626 (5 kpc), embedded in an asymmetric halo extended to the SW A2626 component. Galaxy b (SW) has line emission, and is associated A2626 with the radio source 3C464. A2627 The two galaxies observed appear equally dominant. A2634 The observed galaxy (NGC 7720) is associated with 3C465. RXJ0000.1+0816 The central galaxy shows [N II] and [S II] line emission (EHM99). RXJ0021.6+2803 Galaxy a is the BCG. RXJ0058.9+2657 The central galaxy (NGC 326) is a dumbbell galaxy. A68 Galaxy a is the brighter galaxy, nearer the RASS centroid. A75 Galaxy a is the more likely BCG, but is very close to a bright A75 star, making a observation difficult. Galaxy b is the radio A75 galaxy 0037+209 (Owen et al. 1995AJ....109...14O) A77 This galaxy contains the radio source 0037+292 (Owen et al. A77 1995AJ....109...14O) A84 Galaxy a is the better candidate for the BCG. The redshift for A84 galaxy b quoted by O'Dea & Owen (1985AJ.....90..954O) is from A84 Owen & White (in preparation), for which we can find no A84 subsequent reference. A104 Owen et al. (1995AJ....109...14O) showed that another galaxy A104 in the cluster (harbouring the radio source 0047+241) and west A104 of the dominant one listed in Table 3, at A104 RA 00h 49m 41.8s, Dec +24{deg}26'42" (J2000) has H{alpha} + [NII] A104 emission, but no [OII]{lambda}3727 emission. Z1478 None of the galaxies listed in Table 3 is the central dominant Z1478 galaxy, which lies almost exactly behind a star, at Z1478 RA 07h 59m 40.4s, Dec. + 54{deg} 00' 22" (J2000) Z1953 HRI observations of this cluster suggest that as much as Z1953 two-thirds of the X-ray flux assigned to this system based on the Z1953 RASS observation are in fact due to two X-ray point sources Z1953 within 7 arcmin of the cluster (Ebeling, private communication). Z2089 Galaxy (a) at the X-ray centroid has strong line emission with Z2089 the line ratios ([NII]/H{alpha} and [OIII]/Hbeta) suggestive of Z2089 an AGN. The X-ray source is clearly resolved in a recent ROSAT Z2089 HRI image, supporting its inclusion as a cluster in the BCS. A781 A third galaxy at RA 09h 20m 22.3s, Dec. 30{deg} 30' 53" (J2000) A781 shows H{alpha} in emission, but is foreground at a redshift of A781 0.126 (Ebeling, Henry & Mullis, in preparation). It is not clear A781 whether galaxy a or b is the BCG, although b is brighter. RXJ1053.7+5450 The observed galaxy is to the NW of a very extended X-ray source. RXJ1053.7+5450 There are several other slightly fainter galaxies the SE. A1367 The BCG is NGC 3862, which is associated with the strong radio A1367 source 3C264, and detected as an unresolved point source in ROSAT A1367 images contributing approximately 5 per cent to the total X-ray A1367 emission from the cluster (Edge & Rottgering, A1367 1995MNRAS.277.1580E). NGC 3862 is significantly offset from the A1367 centre of the highly extended X-ray emission, and is observed to A1367 have a weak emission line spectrum ([N II]>H{alpha}, weak [O II]) A1367 with evidence for a blue continuum. HST Observations reveal that A1367 3C264 contains a non-thermal core and jet (Baum et al., A1367 1998ApJ...492R.854B), which could contribute to this blue A1367 continuum. We have observed the galaxy NGC 3860 at A1367 RA 11h 44m 49.1s, Dec. 19{deg} 47' 44" (J2000), which is the A1367 brightest galaxy in the broad cluster core. NGC 3860 has strong A1367 extended line emission, dominated by H{alpha}. A2108 There are three galaxies of equal rank in the core of A2108 this cluster. RXJ1651.1+0459 Hercules A has moderate [O II]{lambda}3727 and weak [O III]) RXJ1651.1+0459 {lambda}5007 ([O III]/[O II]=0.2) emitted by one of two diffuse RXJ1651.1+0459 continuum components separated by 3 arcsec (10.5 kpc; RXJ1651.1+0459 Tadhunter et al. 1993MNRAS.263..999T). A2241 This optical position and redshift of this cluster are confused A2241 in the literature; A2241 appears to be a superposition of an A2241 X-ray-bright cluster at z~0.1 and an X-ray faint group at z~0.06. A2241 The X-ray-bright cluster detected by ROSAT is clearly centred on A2241 PGC 59392 at a redshift z=0.0984, which is also associated with A2241 the radio source 4C32.52C. The galaxies at z~0.06 are more than A2241 10 arcmin from the X-ray peak, and form a separate system not A2241 detected by the RASS RXJ2214.7+1350 The cluster has two central galaxies (NGC 7236/7) sharing a RXJ2214.7+1350 disturbed halo. Z9077 This source is an EMSS cluster, MS 2348.0+2913 (Stocke et al., Z9077 1991, Cat. ). The central galaxy has H{alpha} +[NII] Z9077 emission at a flux of (2.6+/-2.6)x10^15^erg/cm^2^/s discovered Z9077 from narrow-band imaging by Donahue et al. (1992ApJ...385...49D).